Alan T. Wier

Delayed Maturity Associated with Southern Green Stink Bug (Heteroptera: Pentatomidae) Injury at Various Soybean Phenological Stages

Abstract Delayed maturity in soybean, Glycine max (L.) Merr., occurred in response to infestation by southern green stink bug, Nezara viridula (L.), in 4 yr of field studies. Maturity delays followed stink bug infestation that occurred only during the pod set and filling stages (R3–R5.5), and infestations at R3–4 and R5 resulted in delayed maturity more consistently than did infestation at R5.5. Infestation levels of six stink bugs per 0.3 m of row for 7–14 d generally were required to delay soybean maturity. The greatest impact on seed yield and quality parameters followed stink bug infestations that occurred during R3–R5.5, which corresponded closely with the periods of infestation that resulted in delayed maturity. If both delayed maturity and yield reduction are considered, the pod elongation through late pod filling stages were most critical for protecting soybeans from southern green stink bugs.

Management of Insecticide Resistant Soybean Loopers (Pseudoplusia Includens) in the Southern United States

The soybean looper, Pseudoplusia includens (Walker), ranks among the most important of the multitude of pests that threaten soybean annually in the southern United States. With the documentation of resistance to permethrin in 1987, this insect pest has developed resistance to virtually all classes of insecticides to include DDT, cyclodienes, organophosphates, carbamates, and most recently, the pyrethroids. This development is alarming in view of the infrequent use of insecticides on soybean and the rapidity with which resistance has appeared after adoption of an insecticide. The factors responsible relate to the insect’s biology and ecology, which challenge assumptions frequently made when attempting to model development of insecticide resistance in insects. Research progress has been made toward formulation of an insecticide resistance management plan. However, it is evident that expertise and cooperation beyond the soybean community and quite possibly beyond the boundaries of the United States will be necessary to develop and implement a viable strategy.